The automatic monitoring system for ambient air is mainly used for point comparison of ambient air quality monitoring, fine monitoring of urban ambient air quality, pollution source tracing, and smart city construction. The equipment part of the system adopts a small size and modular design, which facilitates the flexible deployment of encrypted networks in a grid. It has strong mobility and is suitable for various environments such as outdoor, industrial parks, and residential areas. Its monitoring accuracy has achieved good results in practical applications in many places within Guangdong Province. Obtain big data analysis, publish and display the results, help government departments carry out refined prevention and control work in advance, reduce the adverse effects of polluted weather, ultimately promote the construction of environmental protection infrastructure, further improve ecological environment quality, ensure social environmental security, and promote social stability and unity.